1. Field
The present disclosure relates to wireless network monitoring technology, and more particularly, to a terminal that monitors a network state using a combination of a packet gap model (PGM) scheme and a channel quality indicator (CQI) scheme, and a system and method for monitoring a wireless network using the terminal.
2. Discussion of Related Art
Wireless network monitoring technology is used to provide a reliable service in a wireless communication environment. For example, a streaming service involves a wireless network monitoring technique for monitoring a network state (e.g., an available network bandwidth or network speed) and based on the current network state, selecting an appropriate media source to be transmitted.
FIG. 1 is a diagram illustrating a common wireless network monitoring technique. FIG. 1 shows a videophone service in which an appropriate image source is selected according to a network state and transmitted.
As shown in FIG. 1, when a first terminal 10 performs a video call with a second terminal 20, the first terminal 10 transmits low-quality video or high-quality video to the second terminal 20 according to a network state obtained through network monitoring. These video sources, i.e., the low-quality video and the high-quality video, should be transmitted at rates of, for example, 700K bits per second or higher and 1.2M bits per second or higher, respectively, for proper playback. The low-quality video and the high-quality video may be generated at the first terminal 10 according to an encoding option.
The first terminal 10 determines, based on the network monitoring results, whether, given a current network state (e.g., an available network bandwidth), only the low-quality video can be processed or even the high-quality video can be as well, selects an appropriate video source from the low-quality video and the high-quality video according to the determination, and transmits the selected video source to the second terminal 20.
However, according to an existing network monitoring scheme, the first terminal 10 transmits measurement packets, i.e., additional packets for measuring a state of a network, to the second terminal 20. In other words, when such existing network monitoring scheme is employed, the first terminal 10 transmits at least two measurement packets to the second terminal 20, and then the second terminal 20 calculates a reception interval between two measurement packets for monitoring the network state. Such network monitoring scheme is referred to as a PGM scheme.
The existing PGM scheme facilitates measurement of both of a non-assured maximum possible speed (a maximum speed available for a service in a current network state) and an assured maximum increment of speed (a maximum speed-up available for one of services with respect to a current network speed for the services without any change in the other services) of the network.
However, the existing PGM scheme may result in a delay in the measurement under a network environment (e.g., a degree of network congestion, communication capacity at a bottleneck, and a probability of loss of a measurement packet) since measurement packets are to be transmitted for network monitoring. Therefore, the network monitoring requires much time for the measurement and leads to a reduced accuracy and reliability of the measurement results.